Abstract: The present disclosure provides rare earth die steel. Mg and B elements are added on the basis of adding rare earth element Y, so that the rare earth element purifies a matrix, and grain boundary occupation by Mg and B is fully utilized to regulate grain network chromium carbides. In addition, the B element can fully improve hardenability of austenite and ensure that non-martensite such as bainite does not appear during the cooling process, and therefore rare earth die steel with high impact toughness and high isotropy is obtained.

Abstract: A high-strength and high-plasticity TWIP steel and a preparation method thereof are disclosed. In the disclosure, comprehensive properties of TWIP steel are improved by inclusion modification with Ce and Ba addition, fine grain strengthening and twinning nanocrystallization; the grain size is controlled by a low-temperature cold rolling, a transient annealing treatment and a low-temperature tempering treatment. Considering the addition of Ce, stacking fault energy of the TWIP steel is reduced, and the formation of twins, and the division of twins into grains are promoted, which further reduces a mean free path of dislocation motion, thereby improving yield strength, and finally obtaining a high-strength and high-plasticity TWIP steel.

Abstract: A high-strength and high-plasticity TWIP steel and a preparation method thereof are disclosed. In the disclosure, comprehensive properties of TWIP steel are improved by inclusion modification with Ce and Ba addition, fine grain strengthening and twinning nanocrystallization; the grain size is controlled by a low-temperature cold rolling, a transient annealing treatment and a low-temperature tempering treatment. Considering the addition of Ce, stacking fault energy of the TWIP steel is reduced, and the formation of twins, and the division of twins into grains are promoted, which further reduces a mean free path of dislocation motion, thereby improving yield strength, and finally obtaining a high-strength and high-plasticity TWIP steel.

Abstract: The present disclosure provides rare earth die steel. Mg and B elements are added on the basis of adding rare earth element Y, so that the rare earth element purifies a matrix, and grain boundary occupation by Mg and B is fully utilized to regulate grain network chromium carbides. In addition, the B element can fully improve hardenability of austenite and ensure that non-martensite such as bainite does not appear during the cooling process, and therefore rare earth die steel with high impact toughness and high isotropy is obtained.